Abstract

The purpose of this study was to clarify the safety and feasibility of a 6-day protocol of bilateral repetitive transcranial magnetic stimulation (rTMS) combined with intensive swallowing rehabilitation for chronic poststroke dysphagia. In-hospital treatment was provided to 4 poststroke patients (age at treatment: 56-80 years; interval between onset of stroke and treatment: 24-37 months) with dysphagia. Over 6 consecutive days, each patient received 10 sessions of rTMS at 3 Hz applied to the pharyngeal motor cortex bilaterally, followed by 20 min of intensive swallowing rehabilitationexercise. The swallowing function was evaluated by the Penetration Aspiration Scale (PAS), Modified Mann Assessment of Swallowing Ability (MMASA), Functional Oral Intake Scale (FOIS), laryngeal elevation delay time (LEDT) and Repetitive Saliva-Swallowing Test (RSST) on admission and at discharge. All patients completed the 6-day treatment protocol and none showed any adverse reactions throughout the treatment. The combination treatment improved laryngeal elevation delay time in all patients. Our proposed protocol of rTMS plus swallowing rehabilitation exercise seems to be safe and feasible for chronic strokedysphagia, although its efficacy needs to be confirmed in a large number of patients.

Abstract

BACKGROUND AND PURPOSE:

Treatment options for stroke-related dysphagia are currently limited. In this study, we investigated whethernoninvasivebrain stimulation in combination with swallowing maneuvers facilitates swallowing recovery in dysphagic stroke patients during early stroke convalescence.

METHODS:

Fourteen patients with subacute unilateral hemispheric infarction were randomized to anodal transcranial direct current stimulation(tDCS) versus sham stimulation to the sensorimotor cortical representation of swallowing in the unaffected hemisphere over the course of 5 consecutive days with concurrent standardized swallowing maneuvers. Severity of dysphagia was measured using a validated swallowing scale, Dysphagia Outcome and Severity scale, before the first and after the last session of tDCS or sham. The effect of tDCS was analyzed in a multivariate linear regression model using changes in Dysphagia Outcome and Severity Scale as the outcome variable after adjusting for the effects of other potential confounding variables such as the National Institutes of Health Stroke Scale and Dysphagia Outcome and Severity scale scores at baseline, acute ischemic lesion volumes, patient age, and time from stroke onset to stimulation.

RESULTS:

Patients who received anodal tDCS gained 2.60 points of improvement in Dysphagia Outcome and Severity scale scores compared to patients in the sham stimulation group who showed an improvement of 1.25 points (P=0.019) after controlling for the effects of other aforementioned variables. Six out 7 (86%) patients in tDCS stimulation group gained at least 2 points of improvement compared with 3 out 7 (43%) patients in the sham group (P=0.107).

CONCLUSIONS:

Because brain stem swallowing centers have bilateral cortical innervations, measures that enhance cortical input and sensorimotor control of brain stem swallowing may be beneficial for dysphagia recovery.